Presently most of various kinds of billboards, fire-fighting electronic indicators and so on us the structure of neon light, electroluminescence (EL) luminescence source panel and fluorescent lamp box. Although the neon lights used by the said billboards have high luminance, they have too high voltage, short life, high electricity wastage and high maintenance cost. The said electroluminescence (EL) luminescence source panel needs 80-100v AC voltage of hundreds of cycles, therefore striking fire easily occurs. Also its luminance is lower and life is shorter. The said cold cathode display device requires the electricity source of more than one thousand voltage so that its life is universal problem except safe problem. Present familiar thin film electroluminescence (EL) luminescence source fire-fighting electronic indicators consumes 3-5 watt according to international and domestic standard size. The fire-fighting electronic indicators is substantially single-colour and its luminance will decrease much after it is used ten thousand hours.
The luminescence device which is formed by matrix arrangement of light-emitting diodes can meet the requirement of outdoor high luminance. However it needs many light-emitting diodes and consumes much electricity. Also its image display effect is poor and visual angle is small so that it has no enjoy.
In a word, the above these display devices have short life, cant work under safe voltage, consume too much electricity power when long continued work, are not advantageous to environment protection and need complex maintenance and too high maintenance cost. Although using matrix arrangement of luminescence diodes can resolve the above safe and life problems, it can't resolve high electricity wastage and poor display effect.